Antenna modules for RFID (Radio Frequency Identification) are used in electronic devices such as mobile phones for installing functions of near field non-contact communication.
Such an antenna module performs communication by utilizing inductive coupling with an antenna coil installed in a transmitter such as a reader/writer. More particularly, when the antenna coil receives a magnetic field from the reader/writer, the antenna module converts the magnetic field into power so as to drive an IC that functions as a communication processing portion.
In order to reliably perform communication, the antenna module is required to receive a magnetic flux of a certain value or more from the reader/writer by using the antenna coil. Therefore, an antenna module according to the prior art is provided with a loop coil in a casing of a mobile phone so as to receive a magnetic flux from the reader/writer by using the coil.
For instance, Patent Document 1 suggests a method in which a flexible cable or a flat cable is disposed around a built-in battery as a method for improving properties of a loop antenna incorporated in a mobile phone apparatus.